Re: sic of my ancestral name becoming "vogue"
Actually, the name Gavin has more history than just what you have mentioned and many people have researched the history and find the name perfectly acceptable to use.
In Ireland, its is a reduced Anglicized form of Gaelic Ó Gábháin or Ó Gáibhín, both of which derive from diminutives of gábhadh ‘want’ or ‘danger’ (the second being the more likely meaning here).
In Scotland, its a reduced form of McGavin, which is believed to be an Anglicized form of Gaelic Mac Gobhann ‘son of the smith’.
In northern English it is from a personal name popular in the Middle Ages in the Middle English form Gawayne as well as the Old French Gauvin. The name was introduced from French versions of the Arthurian romances, where this name was borne by one of the knights of the Round Table, the brother of Galahad and Mordred and a nephew of Arthur.
In Welsh, it is probably from an Old Welsh personal name composed of the elements gwalch ‘hawk’ + gwyn ‘white’, influenced in part by Breton forms.
In French and Swiss French, In some cases possibly Castilianized form of Aragonese Gabín, a habitational name from Gabín, a place in Uesca province, Aragon.